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本文对高应力集中区中疲劳裂纹扩展进行了研究,对两种材料的中心椭圆孔边裂纹板共6个试件进行了低周疲劳试验。为了减少参量计算引起的误差,首先给出了有限宽板中心椭圆孔边裂纹应力强度因子的计算公式,同时对弹塑性材料引入了大范围塑性区修正方法。为了考证公式和方法的正确性,进行了有限元计算。应力强度因子 K 和大范围塑性区修正形式的 K两者都被用作为相应的参量,结果表明:本文发展的大范围塑性修正形式的代表 J 积分的 K,对高应力区疲劳裂纹扩展是一个合适的参量。
In this paper, the fatigue crack propagation in high stress concentration area was studied. Low-cycle fatigue tests were conducted on 6 specimens of cracked plates with central elliptical holes in both materials. In order to reduce the error caused by the parameter calculation, the formula for calculating the stress intensity factor of the crack near the center of an elliptical hole in a finite-width plate is given first. At the same time, a large area plastic zone correction method is introduced into the elasto-plastic material. In order to verify the correctness of the formulas and methods, finite element calculation was carried out. The results show that K, which represents the J-integral of the large-scale plastic correction form developed in this paper, is one for fatigue crack growth in high-stress zone Appropriate parameters.